AAntibioticsAs many as 50 percent of spontaneous preterm births are associated with infections, including sex-ually transmitted diseases such as chlamydia and bacterial vaginosis, as well as urinary tract and gum infections. If you're diagnosed with a bacterial infection, your doctor will probably prescribe a pregnancy-safe antibiotic. Take it as directed and finish the full course.

BBMIYour prepregnancy body mass index, or BMI, should determine how many pounds you put on during pregnancy. "These guidelines are widely accepted," explains Naomi Stotland, M.D., an assistant professor of obstetrics and gynecology at the University of California, San Francisco. To calculate your BMI and also learn your recommended weight gain, visit fitpregnancy.com/BMI. Be aware there is controversy over how much weight obese women (BMI 30 or more) should gain.

CCall Your Doctor Or MidwifeIf you experience:•Sudden swelling in your hands, legs or feet•Vaginal bleeding (see S for spotting)•Fever and/or chills•Severe headache not relieved by Tylenol•A sudden gush or aslow trickle of fluid from the vagina•Lack of or suddenchanges in fetal movement in the third trimester•Nausea or vomiting so severe that you can't eat or drink•Burning or itching when you urinate•Abdominal pain•Blurriness or other vision changes

DDiabetesAbout one in 200 women of childbearing age has diabetes, and another 2 percent to 5 percent develop the condition during pregnancy (gestational diabetes). Whenever the onset, mothers-to-be with diabetes are at risk for pregnancy complications, including preterm delivery and stillbirth. But a Centers for Disease Control study showed that taken before and during early pregnancy, multivitamins may reduce the risk for birth defects in babies of diabetic moms.

EExerciseThe American College of Obstetricians and Gynecologists recommends that pregnant women get 30 minutes of exercise a day (there are exceptions, so be sure to get your doc's or midwife's OK first). Breaking up your activity into three 10-minute or two 15-minute segments will work just as well. Check out our prenatal workouts and postnatal workouts that you can do at home.

FFirst-Trimester ScreeningFirst-trimester Down syndrome screening involves an ultrasound to measure an area at the back of the fetus's neck (nuchal translucency) and a simple test of the mother's blood. The advantage is that it isn't invasive and can't cause a miscarriage. But it's not perfect. "This is a screening test, not a diagnostic one," explains Nicole Karjane, M.D., an assistant professor at Virginia Common-wealth University Medical Center. "A positive screen means the risk that the child has Down is higher, and a negative screen means the risk is lower." That information can help you decide whether to go ahead with chorionic villus sampling (CVS), performed at 10 to 12 weeks, or amniocentesis, done at 15 to 18 weeks; both can definitively diagnose the disorder but pose small risks of miscarriage. First-trimester screening also can't detect fetal neural-tube defects, such as spina bifida.

GGroup B StrepUniversal screening for a bacterial infection called Group B Strep (GBS), which used to be the No. 1 cause of infection in newborns and a significant cause of uterine infections in new moms, has drastically reduced its incidence. Your OB or midwife will take a swab of your vagina and rectum at 35 to 37 weeks. If you carry GBS (10 percent to 30 percent of pregnant women do), you will be treated with antibiotics during delivery, unless you are having a planned C-section.

HHerbal RemediesA recent commentary in Obstetrics & Gynecology says that due to poor quality control and a lack of good studies, there is "no scientific basis" for the belief that herbal medicines are safe during pregnancy. "I ask patients, 'What is this remedy doing for you that might make it worth the chance that it's dangerous?' " says Deanne Williams, C.N.M., a former executive director of the American College of Nurse-Midwives. She and the March of Dimes urge moms to inform their caregivers about any remedy they are taking, whether it's prescription, over-the-counter or herbal.

IIronIron is one of the key ingredients in red blood cells. Anemia, a condition in which the number and/or size of your red blood cells falls below normal, is common in pregnancy. Anemic moms are more likely to be tired and out of breath, and iron deficiency has been linked to an increased risk of preterm birth and low birth weight. Most women have trouble getting enough iron through diet alone, so take a prenatal vitamin with iron. (If constipation is an issue, ask for a prescription for a supplement that also contains a stool softener.)

JThe JohnFrequent bathroom visits during pregnancy are annoying but can help prevent a urinary tract infection (UTI), the most common infection in pregnancy and one that can lead to a more serious kidney infection or preterm labor. That's why your doctor or midwife "dips" your urine at every visit to test for a UTI (many pregnant women have no symptoms). Help avoid infections altogether with these tips:• Urinate after having sex.• Drink lots of water to "flush out" your urinary tract.• Empty your bladder frequently.• When urinating during early pregnancy, lean forward to allow your bladder to empty completely; later, lift your belly.• Call your doctor or midwife if you experience pain or burning when urinating, feel the need to pee again right after going, or have a fever or blood in your urine.

KKegelsDone frequently enough, these exercises that strengthen the pelvic-floor muscles will help prevent urine leaks and may aid in shortening labor and reducing your chance of needing an episiotomy. Whether or not Kegels can improve sexual function remains a mystery. "That's hard to measure," explains Jerri Hobdy, C.N.M., director of the Midwifery Institute at Philadelphia University. "But it probably does. Any woman who's had intercourse can relate to the capacity to tighten those muscles." To do Kegels, slowly tighten and lift the muscles you use to stop the flow of urine. Repeat 10 to 20 times; do three sets a day.

LLibidoSome pregnant women are relieved to not have to worry about birth control; others find pregnancy downright sexy. But for many women, pregnancy can be a libido-sapping experience, at least for the first trimester. "A lot of women say, 'I'm just too tired,' " explains Deanne Williams, C.N.M. "In this case, the woman's needs are going to be No. 1," she adds. "It's not a rejection of your partner and it's not forever, but women should pause and think, 'I'm sending lots of rejection messages. What can I do to make up for that?' " If fear that having an orgasm will cause problems has you cooling your jets, relax. Orgasm, Williams says, will not cause labor if your body's not ready to be in labor.

MMorning SicknessNausea and vomiting affect 70 percent to 85 percent of pregnant women. "The good news is that babies are parasites, so they're usually getting what they need even if you don't," jokes Nicole Karjane, M.D. Treating symptoms as soon as they surface may stop them from progressing to more severe hyperemesis, which often requires hospitalization. In fact, a University of Toronto study found that women who had experienced morning sickness in a previous pregnancy benefited from taking anti-nausea drugs as soon as they found out they were pregnant instead of waiting for symptoms to resurface. If your nausea is severe, your doctor may prescribe medication, but try these simple suggestions first:• Drink lots of fluids; even slight dehydration can worsen nausea.• Eat more frequent, smaller meals; incorporate lemon and ginger flavors.• Try a different prenatal vitamin.• Don't brush your teeth when your nausea is at its worst or right after eating (the gag reflex is stimulated).• Exercise!• Try over-the-counter remedies such as Emetrol, a sugar syrup; Sea-Bands, which apply acupressure to the wrist; or vitamin B6.

NNeural-Tube DefectsTo help prevent neural-tube defects (NTDs) such as spina bifida (and, possibly, cleft palate and some heart defects), all women between the ages of 15 and 45 should take 400 micrograms of the B vitamin folic acid daily. If your prenatal vitamin upsets your stomach, take folic acid by itself. Some women, including those with seizure disorders and women who themselves had an NTD or a previously affected pregnancy, should get 4,000 mcg (4 milligrams) of the vitamin. Diabetics and obese women might also benefit from this higher dosage.

OOral HealthFor years, experts have been aware of an association between periodontal (gum) disease and preterm labor. Preliminary research suggests that a nonsurgical dental procedure called scaling and planing may reduce the chance of preterm birth for women at risk of having babies early. Visit your dentist and, if necessary, a periodontist as part of your pre-conception planning or as early in your pregnancy as possible.

PPartnerAt least one study has found that moms who have the support of a companion during labor and delivery experience fewer complications during childbirth and less postpartum depression. Another showed that women who weren't happy with the amount of emotional support they received during the second trimester had lower-birth- weight babies. Some tips for involving your partner from the very beginning:• Instead of a quick post-appointment analysis in the parking lot before heading your separate ways, schedule prenatal visits around a meal so that you can use a lunch or dinner date to talk about the doctor's visit.•Attend childbirth and parenting classes together. They fill up fast, so register early to ensure you can find a time that's good for both of you.• Buy him a copy of Ian Davis' My Boys Can Swim! (Three Rivers Press) or Dave Barry's Babies and Other Hazards of Sex (Rodale).

QQuickeningYou will probably notice your baby's first movements--or "quickening"--around 20 weeks (sooner if you've been pregnant before, later if you're tall). In your third trimester, your OB or midwife may ask you to do a daily kick count, which tracks those movements. "Kick counts are a good way of reassuring everybody that the baby is doing well," explains Jerri Hobdy, C.N.M.

RRelax!You may worry that anxiety about your pregnancy or other issues will harm your baby, but a 2006 study at Johns Hopkins University concluded that there is no direct association between normal anxiety and pregnancy outcome. Severe or chronic stress can contribute to preterm birth, however.

SSpottingBleeding during pregnancy is scary but common. If you experience spotting or heavier bleeding, call your doctor or midwife right away and be prepared to describe it to her: what color it is, when it started, etc. Bleeding can be caused by everything from the embryo's implantation to intercourse or--unfortunately--miscarriage. The good news is, more than half of all women who experience spotting in early pregnancy go on to deliver full-term babies. If you're bleeding so much that you are changing a pad every hour, or if you feel lightheaded or experience other signs of anemia, go straight to the ER.

TTravel"The recommendations on traveling while pregnant vary depending on your medical history, the point you are in pregnancy and the mechanics of the trip," says Deanne Williams, C.N.M. "If I have a patient in her third trimester, I ask her to weigh the necessity of the trip against her willingness to have her baby wherever it is she's going." Here are tips for moms on the move:• If you're showing and planning to fly, have your doctor write a "prescription" approving you for air travel up until the appropriate date. This can help prevent last-minute glitches.• Carry a copy of your medical records with you, just in case.• If you have a chronic medical condition, are taking any pregnancy-related medication or are allergic to any, be sure to wear medical jewelry to alert emergency personnel (check out laurenshope.com for hip options).

UUltrasoundsWhile ultrasound can be an invaluable tool for diagnosing problems and monitoring fetal development, no one knows the long-term effects of repeated exposure. In most cases, the benefits of a low-level ultrasound exam performed at a doctor's office outweigh the risks, but the same cannot be said for keepsake ultrasounds done at your local mall. In fact, in 2002 the FDA ruled that performing an ultrasound without a doctor's prescription is illegal. "You have a technologist who knows how to do the scan but doesn't know how to interpret it," explains Carol Rumack, M.D., F.A.C.R., chair of the American College of Radiology's Ultrasound Commission.

VVaccinations2005 guidelines call for all women who will be pregnant during flu season (usually November through April) to get a flu shot. The nasal-spray flu vaccine (aka the LAIV, for Live Attenuated Influenza Vaccine) is still not recommended for pregnant women.

WWorkplace RightsBefore you announce your pregnancy, learn your rights under the Family & Medical Leave Act by checking out the U.S. Department of Labor's website (dol.gov). And keep in mind that the Pregnancy Discrimination Act requires employers to treat pregnancy like any other medical condition. For example, if you're temporarily unable to do your job because of pregnancy complications, your boss has to provide you with modified tasks, different assignments, disability leave or leave without pay just as she would someone temporarily disabled by back surgery. For more information, visit eeoc.com.

XX-raysWondering whether exposing your baby to radiation-even small amounts--is worth the potential risk? "If the X-ray is medically necessary, I'd say, 'Do it,' " says Louis K. Wagner, Ph.D., chief physicist and professor at the University of Texas Medical School at Houston. "If there is any doubt and if the procedure involves the abdomen, perhaps a second opinion should be requested." Try to get dental X-rays before or after your pregnancy.

YYogaA 2005 study comparing pregnant women who walked for half an hour twice a day to those who practiced yoga for an hour a day found that the latter had fewer complications, including pregnancy-induced hypertension and preterm delivery. "Yoga also helps decrease some of the common discomforts of pregnancy, such as back pain and sciatica, and helps build the strength and endurance you'll need for labor and delivery," says Marcy White, a nurse and certified childbirth educator who teaches prenatal yoga. Yoga, she adds, allows you to "connect" with your unborn child: "You learn to focus your mind on your body, your breath and your baby."

ZZ'sA study conducted by Kathy Lee, R.N., Ph.D., found that women who slept fewer than six hours per night in the last few weeks of pregnancy labored for an average of 12 hours longer and were 4.5 times more likely to have a C-section than women who slept more than seven hours. Some sleep-enhancing suggestions:• Snuggle up with a comfortable "pregnancy pillow," such as Boppy's 24/7 Body Pillow ($65 at Target).• Because your body "runs hot" during pregnancy, turn down the thermostat, dress in lighter pj's and use fewer covers.• If you've started snoring or suffer from nasal congestion that keeps you awake, try Breathe Right nasal strips.